Foam
Block foam is foam manufactured from polyurethane. It is manufactured into large blocks that are later cut down to the required size.
This type of foam is the most common material used as a sofa interior. Foam is firm and supportive and lends a more tailored appearance to a sofa. Block foam can be found in the seat cushions, arm pads and back cushions of sofas.
Block foam is soft and durable and comes in many different densities. Over the years, foam may compact and lose a little volume however this may be minimised by turning the cushions occasionally to change the areas of wear.
Fibre
Fibre is a type of filling used in sofas that is manufactured from polyester. You may be familiar with polyester fibre as it can be found inside other popular products such as teddy bears, pillows and duvets.
Fibre is a very popular choice for a sofa filling as it is very versatile and is a cheaper option to duck feathers or down. It is used in the seat cushions, arm pads and backs of sofas. It is also the filling of choice for most scatter cushions.
Sofas that use fibre in the seat cushions tend to have a soft and lived in look, requiring some maintenance to keep them looking their best. Daily turning and plumping of the cushions is needed to maintain comfort and to prevent them from going flat.
Fibre is mostly used in sofa back cushions for softer feel.
Foam & Feather
This is an excellent method for seat cushions as the core consists of a higher density foam, wrapped top and bottom with duck or goose feathers. These types of cushions combine the best characteristics of feather and foam, the softness, support and comfort of feather mix combined with the stability and resilience of foam.
A sofa using foam and feather will last longer than a sofa using foam only. This method is arguably equivalent to pocket springs in terms of durability and comfort.